Reduced friction catheter introducer and method of manufacturing and using the same

ABSTRACT

Tear-away sheath introducers for catheters, methods for making such introducers, and methods for using such introducers are described. A splittable sheath introducer may include a sheath, a hub disposed at a proximal end of the sheath, a valve included with the hub, and a valve actuator movable from a first position to a second position, the valve actuator opening the valve when in the second position. The valve actuator may include a retaining feature that interacts with the hub to connect the retaining member to the hub.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 13/849,261, filed Mar. 22, 2013, now U.S. Pat. No. 9,101,737, which is a continuation of U.S. patent application Ser. No. 12/399,749, filed Mar. 6, 2009, now U.S. Pat. No. 8,403,890, which is a continuation-in-part of U.S. patent application Ser. No. 11/531,339, filed Sep. 13, 2006, now U.S. Pat. No. 8,932,260, which is a continuation-in-part of U.S. patent application Ser. No. 11/288,959, filed Nov. 29, 2005, which claims the benefit of priority to U.S. Provisional Patent Application No. 60/631,397, filed Nov. 29, 2004, each of which applications is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The invention relates to medical devices and methods for manufacturing such medical devices. In particular, the invention relates to introducers for catheters, methods for making such introducers, and methods for using such introducers. More particularly, the invention relates to self-sealing sheath introducers (both tear-away and non-tear-away), methods for manufacturing such introducers, and methods of using such introducers in medical procedures.

BACKGROUND OF THE INVENTION

Tear-away sheath introducers (“sheath introducers” or “introducers”) and their use as medical devices are well known in the art. See, for example U.S. Pat. Nos. 6,814,718; 6,808,520; 6,808,509; 6,796,991; 6,740,101; 6,712,791; 6,712,789; 6,695,810; 6,641,564; 6,632,234; 6,623,460; 6,599,302; 6,361,559; and 5,558,652; as well as U.S. Patent Application Publication Nos. 2004/0260243, 2004/0254534, 2004/0176781, 2004/006330, 2004/097863, and 2002/072789, the disclosures of which are incorporated herein by reference. These introducers are used in medical procedures to insert a catheter into the body and provide vascular access to the vessel of a patient. The catheters are inserted via the introducers by first using a needle to create an access site. A dilator is then used to dilate the access site to allow a larger-diameter sheath introducer to be introduced into the vessel through the access site. The catheter is then inserted through the sheath introducer and into the vessel. After the catheter has been inserted, the sheath introducer is removed, leaving the catheter in the vessel.

As shown in FIG. 19, conventional tear-away (or split) sheath introducers 100 usually contain four major components: (1) a dilator 140; (2) a tear-away sheath hub 111; (3) a tear-away valve 113; and (4) a tear-away sheath 130. The dilator 140 facilitates insertion of the sheath introducer 100 into the vascular system and maintains the inside diameter of the sheath 130 during insertion. The dilator 140 is normally locked into the hub 111 in order to keep it seated within the sheath 130. The dilator 140 typically contains a tapered tip 142 to facilitate insertion into the vascular system with the other end 144 of the dilator containing a standard medical luer hub 146. Both the distal end 142 and the proximal end 144 of the dilator 140 are usually manufactured of a rigid polymer.

The tear-away hub 111 provides a means to contain the valve 113 while connecting the valve 113 and the sheath 130. The hub 111 typically has a “T” shape with the opposing ends of the “T” being grasped and pulled to split both the valve 113 and sheath 130. Thus, the hub 111 provides a mechanism to split the sheath 130 into two portions and allow the introducer to be split and removed from around the catheter. The hub 111 is also often manufactured of a rigid polymer.

The tear-away valve 113, however, is typically made of a flexible material (such as silicone) that provides a self-sealing slit. The valve 113 may be designed as one piece that tears in half during the splitting procedure, or as two (or more) pieces that separate from each other during the splitting procedure. With conventional introducers, the valve 113 is encapsulated by the hub 111.

The tear-away sheath 130 is normally manufactured as a thin-walled structure, often as an extrusion. The extrusion contains splitting means, i.e., score lines that facilitate splitting or a self-splitting propagating material (such as linearly-directional extrusion). The proximal end 132 of the sheath 130 is attached to the hub 111 using over-molding or any other known attachment mechanism. The distal end 134 of the sheath 130 can be tapered to provide a smooth transition at the dilator/sheath interface.

To use the introducer 100, it is inserted in the desired vessel. Then the dilator 140 is unlocked from the hub 111 and removed to allow room for a catheter (or any similar medical device) to be inserted into the sheath. The valve 113 remains stationary inside the hub 111 and blocks air and/or fluid from flowing through the sheath 130 and hub 111 when they are left behind after the dilator is removed. The valve 113 keeps the passage 105 clear until a catheter is inserted into the passage 105 through the valve.

The introducer 100 is typically used for larger catheters, i.e., those with a diameter of 12 to 16 French. These larger-diameter introducers are rigid due to their diameter and the material used to construct them. This rigidity allows the large catheters to overcome the frictional forces needed to push the catheter through the valve.

But inserting smaller catheters into smaller introducers is more difficult. Typical introducers designed for smaller catheters (i.e., those 3 to 12 French in diameter) are made with open communication between the access site and the vascular system once the dilator is removed. This open configuration exists because smaller catheters, due to their smaller diameter and material, are not rigid enough to overcome the frictional forces needed to push the catheter through the valve. In other words, it is like trying to “push” a rope through a hole: the rope (i.e., catheter) does not remain rigid enough for a user to push it through the hole (i.e., valve).

The open configuration between the vascular system and the environment, however, allows two serious clinical problems. First, air embolism into the vascular system which can result in patient injury and/or death. And second, release of potentially infectious bodily fluids (including blood) into the environment, resulting in exposure to the health care provider.

SUMMARY OF THE INVENTION

The invention relates to tear-away and non-tear-away sheath introducers for catheters, methods for making such introducers, and methods for using such introducers. The sheath introducers contain movable valves that are encapsulated in a movable housing that allows the valve to move along the axis of the introducer. As the movable valve and housing travel along the axis, a portion of the hub protrudes past the valve and is exposed. As well, the sheath introducers can also contain a stationary valve and housing that can be opened to expose a portion of the hub when a conduit penetrates the stationary valve. The conduit can include a one-way valve actuator that can penetrate and open the valve, yet remain attached to a portion of the introducer when the introducer is split for removal from a patient. In both instances, the protruding portion of the hub contains a friction-free pathway for a catheter into the sheath introducer. The introducers can therefore be used with any catheter, regardless of the size or material, because of the reduced or eliminated frictional force between the catheter and introducer.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description of the invention can be understood in light of FIGS. 1-23, in which:

FIG. 1 is a side perspective view(s) of the introducer assembly in one aspect of the invention;

FIG. 2 is a side perspective view of a two-piece flexible valve in one aspect of the invention;

FIG. 3 is a side perspective view of a dilator in one aspect of the invention;

FIGS. 4 and 5 are section views of a valve housing in one aspect of the invention;

FIGS. 6 and 7 depict the introducer assembly in another aspect of the invention;

FIG. 8 is a side view(s) of the sheath introducer in another aspect of the invention;

FIG. 9 is a side perspective view(s) of the sheath introducer in even another aspect of the invention;

FIG. 10 is a side perspective view(s) of the sheath introducer in yet another aspect of the invention;

FIGS. 11-12 show a single-piece valve in another aspect of the invention;

FIGS. 13-14 depict view(s) of the single-piece valve and sheath hub in another aspect of the invention;

FIGS. 15-17 depict view(s) of methods of increasing the attachment between the sheath and the sheath hub in another aspect of the invention;

FIG. 18 shows the operation or the sheath introducer in one aspect of the invention;

FIG. 19 illustrates a conventional sheath introducer;

FIGS. 20-21 depict view(s) of methods of increasing the attachment between the sheath and the sheath hub in another aspect of the invention;

FIGS. 22-23 illustrate an introducer containing a stationary valve that is opened by a movable conduit;

FIGS. 24A and 24B depict perspective views of a sheath introducer including a stationary valve and valve actuator according to one embodiment;

FIG. 25 is a cross sectional side view of the sheath introducer of FIGS. 24A and 24B;

FIGS. 26A-26C are various views of the valve actuator of the sheath introducer of FIGS. 24A and 24B, according to one embodiment;

FIG. 27 is a perspective view of a top cap portion of a hub of the sheath introducer of FIGS. 24A and 24B; and

FIGS. 28A and 28B are cross sectional side views of the sheath introducer of FIGS. 24A and 24B, showing actuation of the valve actuator.

FIGS. 1-28B presented in conjunction with this description are views of only particular-rather than complete-portions of the devices and associated methods of making and using these devices. Together with the following description, the Figures demonstrate and explain the principles of the devices and associated methods. In the Figures, the thickness of layers and regions are exaggerated for clarity. The same reference numerals in different drawings represent the same element, and thus their descriptions will be omitted.

DETAILED DESCRIPTION OF THE INVENTION

The following description provides specific details in order to provide a thorough understanding of the invention. The skilled artisan, however, would understand that the invention could be practiced without employing these specific details. Indeed, the invention can be practiced by modifying the illustrated method and resulting device and can be used in conjunction with apparatus and techniques conventionally used in the industry. For example, the invention is described as a micro-introducer for small catheters (3F-10F in size), but could easily be adapted for any size of catheter or device regardless of the size or intended use. Further, while the invention is described for use with catheters for vascular access, it could be used with any similar device that is used to grant a physician (or other user) access to a part of the body, whether human or animal.

The invention includes a tear-away or non-tear-away sheath introducer that contains a movable valve and housing that when moved, allows a portion of the hub to protrude through a valve and be exposed. The protruding portion of the hub contains a friction-free pathway for the catheter. Any inducer having these properties can be used in the invention, including the sheath introducer described below and illustrated in the Figures.

The sheath introducer of the invention contains several primary components. First, dilator means used to dilate the vascular system and create a pathway for the catheter. Second, means for sheathing the dilator means to protect it from the vascular system. And third, valve means for keeping the pathway created by the dilator closed until the catheter needs to be inserted.

One example of the sheath introducer is illustrated in FIG. 1 where the introducer 10 contains dilation means comprised of a dilator hub 1 and a dilator shaft 2. The dilation means is configured to fit within the sheath means comprised of a sheath hub 7 and a sheath 8. The introducer 10 also contains valve means comprised of a valve with left and right halves (4 and 5) contained within valve housing having right and left halves (3 and 6) that is attached to the sheath hub 7.

FIGS. 2-5 illustrate detailed views of each of these components. FIG. 2 depicts one half of the valve 4, FIG. 3 illustrates the dilator 1, and FIGS. 4-5 show the different views of the valve housing 3. In FIG. 2, the valve contains retention means for retaining the valve to the valve housing. Any retention means known in the art can be used, including retention member 12 which seats into a corresponding structure in the valve housing such as the valve retention slot 15. The valve has a size and shape substantially the same as the inner part of the valve housing to which it is retained. Accordingly, the valve half 4 depicted in FIG. 2 is substantially circular and with a size that fits within the corresponding inner surface of the valve housing 3 shown in FIGS. 4-5. The valve can be manufactured from any suitable medical material, including flexible materials like silicone or polyurethane.

FIG. 3 depicts one example of a dilator of the introducer 10. The dilator 31 can contain any standard medical luer hub, including a hub 1 with a gripping mechanism (such as finger grips 11) and locking mechanism (such as locking ears 9) as shown in FIG. 3. The locking mechanism locks the dilator 31 into the valve housing by using, for example, the locking channel 16 contained in the valve housing 3 and 6. The dilator 31 also contains a shaft 2 with a tapered section for dilating the vessel into which it is inserted. The dilator 31 can also be manufactured from any suitable medical material, but should be made fairly rigid, yet flexible enough that it can be maneuvered into the desired vessel by a user.

FIGS. 4 and 5 depict one example of the internal geometry of the valve housing 3. The valve housing 3 contains any means for securing the valve housing to the sheath hub 7. In FIGS. 4 and 5, the securing means comprises snap features 13, which secure the valve housing 3 to the sheath hub 7 using the mating snap feature 21 (shown in FIG. 6). Using the securing means keeps the valve housing (and therefore the valve) in a closed position until it is needed to be opened (i.e., such as when the catheter is inserted).

The valve housing 3 also contains any known means for positioning it with the sheath hub. An example of this positioning means is depicted in FIGS. 4 and 5, where a guide slot 15 and stop post 20 mate with the guidepost 22 of the sheath hub 7 (shown in FIG. 6). The exterior of the valve housing contains grips 14 that can be employed by the user in the splitting procedure. The valve housing 3 is constructed of any suitable medical material that provides the desired rigidity, such as rigid polymeric materials.

The valve housing 3 can also contain any known interlock mechanism between the two halves of the valve housing. An example of this interlock mechanism is lock 19 that, when the halves are assembled together, serves to maintain uniform travel between both halves of the valve housing. This interlock mechanism can be supplemented with any known mechanism, including the detachable interlock features 17 and 18.

FIGS. 6 and 7 illustrate the various components of the introducer when assembled together. In FIGS. 6 and 7, the sheath hub 7 and the sheath 8 are attached together into an assembly by any attachment means. Examples of suitable attachment means include insert molding or any mechanical attachment, such as a friction fit, locking snap fit, solvent or UV bond.

The sheath hub 7 contains several features for its operation. One such feature includes valve snap fit grooves and edges 21. These two components, along with the snap feature 13, work together to snap the valve housing 3 (and 6) to the sheath hub 7. Of course, any similar mechanism can be used to snap these two components to each other. The sheath hub 7 also contains the guide slot 22, as mentioned above, that guides the valve housing 3 (and 6) and the hub to the correct location relative to each other.

The sheath hub 7 also contains a valve penetration means. The valve penetration means operates to penetrate the two halves of the valve 4 and 5, thereby providing an opening in the valve. Any penetration means known in the art can be used for this function. As depicted in FIGS. 6 and 7, the penetration means comprise member 23 that is configured to fit between the two halves of the valve 4 and 5. The penetration member 23 opens the two halves of the valve when it is forced between them by any action which pushes the member 23 through the valve.

The valve penetration means need not physically force (i.e., push) the valve halves 4 and 5 apart to penetrate the valve. In this aspect of the invention, the member 23 penetrates the valve halves 4 and 5 when the valve housings are pulled apart to expose the member 23. The valve housings can be pulled apart by the mechanisms described below.

When the penetration member 23 opens the valve in either of these manners, port 24 is exposed. The port 24 is the location where the catheter (or similar device) is inserted. Unlike the conventional introducers where the catheter is forced between the valve (which creates a friction force that must be overcome by a user), the catheter can be inserted in the port 24 of the introducers. The port 24 can be configured to have less friction than that required in conventional devices by providing an inside diameter slightly larger than that of the catheter insertion member. Alternatively, the port can be configured to have substantially no friction (“friction-free”) by providing an inside diameter significantly larger than that of the catheter insertion member. As well, the port 24 can be configured to have less or substantially no friction by providing a coating on the inside of the port 24 and/or the outside of the catheter.

The sheath hub 7 also contains activation means. The activation means is used to force the penetration member 23 up through the valve halves 4 and 5, move the valve halves (and housing) down over the member 23, or to pull the valve halves apart, to thereby open them and expose member 23 containing port 24. Any mechanism that operates in this manner can be use as the activation means. In the sheath hub depicted in FIG. 8, the activation means pulls the valve halves apart and comprises a reaction force member 25 that is formed on the bottom edge of the sheath hub 7. When pressure is applied to the reaction force member 25 by the user, it depresses the valve housings 3 and 6 and forces the valve halves 4 and 5 apart. Of course, any other known mechanism could be used to push or pull the valve apart.

FIG. 8 depicts the introducer in a position ready to accept a catheter. In FIG. 8, the penetration member 23 protrudes out of the valve halves 4 and 5. The penetration member 23 need only protrude enough so that port 24 is exposed enough for a catheter to be inserted. Typically, the port 24 protrudes from about 0.025 to about 0.05 inches above the valve. In one aspect of the invention, the port 24 protrudes about 0.05 inches above the valve.

FIG. 9 depicts one part of a method for using the introducer 10. After the introducer 10 has been inserted into the desired vessel, the catheter (not shown) is inserted through the introducer. Then, the user presses on the grips 14 to cause the valve housing 3 and 6 to separate from each other. As the pressing continues, the valve halves 4 and 5 and the sheath hub 7 then separate from each other. Once this initial separation has occurred, the user can continue pull on the ends of the separated portions to continue separating the introducer.

FIG. 10 illustrates another part of a method for using the introducer 10. In step 1, the introducer 10 has been inserted in the desired part of the vascular system, i.e., the desired vessel. Next, as shown in step 2, the dilator is then removed from the introducer. As shown in step 3, removing the dilator still leaves the valve in a closed position. Next, using the actuating mechanism a user makes the penetration member penetrate the valve in any of the methods described above so that valve is opened with the port 24 exposed. Then, the catheter (not shown) is inserted into the introducer as shown in step 4. Finally, the introducer is removed by the splitting procedure as shown in step 5.

In some embodiments, the introducer can be configured so that the valve is stationary. In these embodiments, the stationary valve can be opened to expose a portion of a hub when conduit means penetrate the stationary valve. With a portion of the hub exposed, the catheter can then be inserted as described above.

One example of these embodiments is illustrated in FIGS. 22-23. FIG. 22 depicts an assembled introducer 105 without a dilator. The assembled introducer 105 contains a sheath hub bottom 107 containing a sheath hub top 118, and valve means comprised of a stationary valve 104 contained within a valve housing 106. The assembled introducer 105 also contains conduit means (i.e., conduit 110) that can move along the axis of the assembled introducer 105.

The valve 104 can be configured to be stationary within the assembled introducer 105 using any known mechanism. In the embodiments illustrated in FIGS. 22-23, the valve 104 is configured to be stationary by matching the extensions 112 of the valve with corresponding indentations 114 within a press fit generated between the sheath hub top 118 and valve housing 106. In other instances, though, the extensions 112 could be configured to match indentations made in the valve housing 106 (not shown). In yet other instances, the valve can be configured to be stationary by means of any known adhesive.

The valve housing 106 houses the stationary valve 104 and therefore the bottom of the housing 106 can be configured to substantially match the shape of the valve 104. As well, since the valve housing 106 is located on the sheath hub top 118, the bottom of the valve housing 106 can be configured to substantially match the upper surface of the sheath hub top 118. As depicted in FIG. 22, these matching surfaces can be substantially flat. But any other matching shapes for these surfaces can be used, including ridged, notched, or an interlocking snap fit.

The valve housing 106 also surrounds the conduit means (i.e., conduit 110). Accordingly, the inner surface of the valve housing can be configured to substantially match the outer surface of the conduit 110. As depicted in FIG. 22, these two matching surfaces can be configured as substantially circular in shape. But other geometries for these surfaces can be used, including substantially rectangular, substantially oval, substantially polygonal, or a male/female keyway.

The conduit 110 moves along the axis of the assembled introducer 105 from a first position shown in FIG. 22 to a second position shown in FIG. 23. In the first position, the bottom 115 of the conduit remains above the closed valve. In the second position, the bottom 115 of the conduit has pierced the valve and forced the valve into an open position. With the valve in this open position, a catheter can be inserted though the conduit 110 and into the sheath 108.

In other embodiments, the conduit 110 can move into an intermediate position anywhere between the first and second positions. The intermediate position can be selected so that the valve is opened by any desired amount. For example, the intermediate position for the conduit 110 can be selected so that a partially opened valve would allow only a small amount of blood to be exposed, ensuring that the introducer was located correctly in a vein.

The conduit means can have any configuration allowing it to operate in this manner. Thus, the outer surface of the conduit can be configured to be slightly smaller than the inner surface of the valve housing, allowing the conduit to move easily relative to the valve housing. If desired, additional mechanisms like depth control detents, springs, or coatings can be used to increase—or, if necessary, decrease—the ability of the outer surface of the conduit to move relative to the inner surface of the valve housing.

In some instances, the outer surface of the conduit 110 and the inner surface of the valve housing 106 can be configured so that the conduit can be retained in the first and second positions. Any retaining means known in the art can be used, such as markings, depth control detents, springs, threads or the retaining means illustrated in FIGS. 22-23. In these Figures, the retaining means comprises at least one notch 121 on the outer surface of the conduit 110 that substantially matches indentations 123 and 125 on the inner surface of the valve housing 106. The two (or more) sets of indentations are located where the notch 121 will insert when the conduit 110 is in the first and second positions.

The bottom 115 of the conduit 110 can be configured so that it pierces and opens the stationary valve 104. Thus, the bottom 115 of the conduit can be configured with any shape that will operate in this manner. In some instances, the bottom 115 is typically given a substantially pointed or substantially tapered shape. The bottom of the conduit can therefore initially open the valve and as the conduit moves further down, the opening in the valve becomes wider and wider allowing for a substantially friction-free passage way through the valve. In some instances, the bottom of the conduit can be rounded to prevent damage to the valve.

The top 127 of the conduit 110 can be configured with any shape so that it guides the placement of the catheter. One example of such a shape is depicted in FIGS. 22 and 23 where the top of the conduit comprises a substantial conical shape. The conical shape guides the placement of the catheter through the top of the conduit and into the inner chamber 120 of the conduit 110. The conical shape can, in certain instances, be smooth and rounded so that it is easier to be pushed by a user to open the valve.

Once the assembled introducer 105 is located in the desired location, the user can open the valve easily by pressing on the top of the conduit means. This action forces the conduit 110 from the first position into the second position, and opens the valve. The user can then place the tip of a catheter in the top of the conduit. As the user pushes on the catheter, the tip is guided from the top of the conduit 110, though the inner chamber 120, past the opened valve, out the bottom of the conduit, and then into the sheath 108.

Reference is now made to FIGS. 24A-28B, which describe various aspects of a sheath introducer including a stationary valve that can be opened via penetration of conduit, according to one example embodiment. As it shares various aspects in common with the sheath introducers described in previous embodiments, only selected details regarding the present sheath introducer are described below.

As shown in FIGS. 24A, 24B, and 25, the introducer 205 includes a stationary slit valve 204 housed in a sheath hub 207, which in turn is disposed at the proximal end of the sheath 108. The sheath hub 207 includes a top cap 206 that is placed atop the valve 204. Though a slit valve is depicted here, other types of valves may also be employed in the introducer. As before, the valve 204 includes extensions 212 on a bottom surface thereof that are received into corresponding indentations 214 defined in the sheath hub 207 to enable the valve to seat therein.

A valve actuator 210 is also shown in FIGS. 24A, 24B, and serves as one example of a conduit to open an introducer valve, such as the valve 204. As shown in FIG. 25, the actuator 210 is received in a cavity 240 defined by the hub top cap 206 and is movable by a user to selectively open the valve 204 in preparation for insertion through the introducer of a catheter or other device, as will be described. Note that, though configured as separate pieces, the hub 207 and top cap 206 can be integrally formed. Note further that the valve actuator 210 in the present embodiment is substantially coaxial with the longitudinal axis of the introducer 205, though in other embodiments the actuator can be off-center with respect to the longitudinal axis.

Reference is now made to FIGS. 26A-26C, which depict further details regarding the actuator 210 as an example of a conduit according to the present embodiment. As shown, the actuator 210 includes a bottom 215, a top 227, and a conduit pathway 220 defined therebetween. The top 227 includes a ridge and is defined so as to enable a user of the introducer to press the actuator 210 with a downward force in order to selectively open the valve 204 with the actuator bottom 215. An extended surface 215A is included at the actuator bottom 215 and is shaped so as to penetrate the slit valve 204 when the actuator is pushed downward, thus opening the valve and enabling a catheter to pass through both the conduit pathway 220 of the actuator and the valve with minimal resistance. In the present embodiment the extended surface 215A is shaped as a partial cylinder to define a C-shaped cross sectional shape, but it is appreciated that other shapes and configurations are possible for the extended shapes in other embodiments. For instance, in one embodiment the extended surface could define a U-shaped cross sectional shape.

As mentioned, the conduit pathway 220 extends through the actuator 210 to enable a catheter to pass therethrough after the actuator has opened the valve 204. In the present embodiment, the surface of the conduit pathway 220 is conically shaped so as to guide the catheter in its passage through the actuator. As best seen in FIG. 26A, the actuator 210 includes a longitudinally extending channel defined through the side of the actuator body. The channel 230 enables the catheter to pass through and be released from the actuator after placement in the patient vasculature during peel-away of the introducer sheath from the vessel insertion site. Note that, though it is non-splittable in the present embodiment, the actuator in another embodiment can be formed as splittable.

FIGS. 26A-26C further depict a plurality of interference features defined on the side of the body of the actuator 210. In the present embodiment the interference features include a plurality of teeth 232 circumferentially defined in a longitudinally stacked arrangement about a portion of the actuator body. The teeth 232 circumferentially extend from either side of the channel 230 to a raised tongue 234 also defined on the side of the actuator 210 opposite the channel. Of course, other interference features in addition to what is described herein, including features disposed at other locations on the actuator, are contemplated.

The teeth 232 of the actuator 210 are configured to engage with corresponding interference features defined in the cavity 240 of the top cap 206, namely, teeth 242 defined on the inside surface of the cavity. FIG. 27 shows the top cap 206 in an exploded state along its split line, and further depicts the various locations for the teeth 242 according to the present embodiment. The locations of the teeth 242 are configured to enable the top cap teeth to engage with the teeth 232 of the actuator 210 when the actuator is pressed downward into the top cap cavity 240 in order to open the valve 204. The teeth 242 of the top cap cavity 240 are configured to engage the actuator teeth 232 in such a way as to enable further downward (one-way) movement of the actuator, but to prevent upward actuator movement. In other embodiments, however, it is appreciated that the actuator can be configured to be resettable or reversible, via a spring and two-way interference features for instance, so as to enable the actuator to be pressed downward to open the valve, yet be upwardly retractable so as to close the valve again, if desired.

Grooves 244 are defined on the inside surface of the top cap cavity 240 to engage with the tongue 234 defined on the side of the actuator 210 when the actuator is received in the top cap cavity. Engagement of the actuator tongue 234 with one of the top cap cavity grooves 244 enables the actuator to slide longitudinally within the cavity 240, while causing the actuator to retain physical engagement with the respective half of the top cap 206 when the top cap, together with the rest of the introducer 205, is split apart in order to remove it from the vessel insertion site. In brief, the side surfaces of the teeth 242 adjacent the groove of the top cap cavity 240 are angled such that the actuator tongue 234 is captured in and retained by the groove, even when the top cap is split. This prevents the actuator 210 from falling out of the introducer 205 when split. Thus, the tongue 234 and/or grooves 244 operate as retaining members and therefore serve as one example of means for preventing separation of the valve actuator from a portion of the hub when hub is split. Note, however, that other means for providing this functionality may be included in the introducer. For instance, the valve actuator can be attached to a portion of the sheath hub by a living hinge, a tether, a magnetic feature, etc. These and other means for preventing such separation are therefore contemplated.

The top cap 206 includes tabs 246 that are configured to be received by corresponding grooves 248 (FIG. 25) defined in the sheath hub 207 in order to mate the top cap with the sheath hub and secure the valve 204 in a sandwiched configuration therebetween. The engagement between the top cap 206 and the sheath hub 207 can be secured mechanically (e.g., snap-fit), adhesively, or by other bonding methods (e.g., ultrasonic bonding). In the present embodiment, the composition of the actuator 210 includes polypropylene, but in other embodiments an acrylic, e.g., polymethyl methacrylate, or other thermoplastic or thermoset may be employed for forming the actuator. In one embodiment, the actuator 210 is colored to indicate the French size of the introducer 205. The principles of the present embodiment may be extended to introducers of a variety of French sizes, as was described in connection with previous embodiments.

Reference is made to FIGS. 28A and 28B in describing the opening of the valve 204 by the actuator 210 of the introducer 205. As shown in FIG. 28A, with the actuator 210 in an upward first position, the extended surface 215A of the actuator is above and is not in contact with the valve 204. This configuration is useful for reducing the risk of air embolism and/or blood leakage via the introducer 205 while the introducer is partially inserted into a vessel of the patient. When the actuator 210 is pressed downward by the user, as shown in FIG. 28B, the actuator is moved from the first position to the second position where it is brought into contact with the valve 204 such that the extended surface 215A penetrates the slit of the valve, thus opening the valve. Note that the movement of the valve actuator 210 from the first position to the second position is performed in one embodiment via direct finger pressure on the valve actuator in a direction that is substantially coaxial with a longitudinal axis of the valve actuator. This results in a balanced force imparted on the introducer during valve opening.

This provides a clear path via the actuator conduit pathway 220 for the catheter to pass through actuator, sheath hub 207, and sheath 108 for placement in the patient's vasculature. Later, when the catheter is placed, the introducer 205 can be split and removed from the vessel insertion site. Upon splitting, the tongue and groove engagement of the actuator 210 with the top cap cavity 240 enables the actuator to be retained with a corresponding split portion of the top cap 206. During the introducer splitting and removal, the already-placed catheter will pass through the actuator channel 230 to free the catheter from the actuator, as the actuator is non-splittable in the present embodiment.

In one embodiment, the composition of the sheath hub 207 includes a clear material, such as acrylic, e.g., polymethyl methacrylate, so as to enable the sheath hub to be translucent. This in turn enables a lower portion 240A of the cavity 240 (FIG. 28B) defined in the sheath hub 207 to be visible by the user. So configured, the cavity lower portion 240A can be observed, such as to determine when venous access has been established as evidenced by the sight of blood in the cavity lower portion. In one embodiment, one or more magnifiers 250 can be formed in the sheath hub 207, as seen in FIGS. 24A and 24B, to assist in observation of the cavity lower portion 240A. The magnifiers can be defined by any acceptable process, including overmolding, post-manufacture machining, etc. Also, the surface of the sheath hub 207 can be polished to increase visibility therethrough.

The introducers described above can be modified and enhanced with several optional features. One of these modifications is a modified valve 30 as depicted in FIGS. 11 and 12 that comprises a base 32, extensions 34, and channel portion 36. The base 32 of the valve 30 is configured with a size and shape substantially similar to the valve housing in which the valve 30 rests. The valve 30 can optionally contain an indentation 35 of any shape and size that will help the valve split.

The extensions 34 are designed to extend upwards from the valve 30 towards the dilator of the introducer. Like the base 32, the extensions 34 will abut the valve housing, but the sides rather than the bottom. Accordingly, the size and shape of the extensions 34 are selected to substantially match the inner surface of the valve housing which will enclose the valve 30. The extensions 34 contain a notch(es) 38 that correspond to the notches 50 provided in the protruding member 41 (as described below).

The channel portion 36 of the valve 30 also extends in an upward direction toward the dilator of the introducer. As shown in FIG. 12, the inner surface 37 of the channel portion 36 will abut the outer surface of the outside of the protruding member 41 and is accordingly given a size and shape substantially matching the protruding member 41. The length of the channel portion 36 is also selected to substantially match the protruding member 41 so that port 44 can be exposed when desired.

The upper surface 42 of the channel portion contains a slit 40. The slit 40 does not extend the entire way across the channel portion 36 and so is a non-tear away slit. The slit 40 is held in a closed or sealed position (position A in FIG. 13) by the valve housing and sheath hub. The slit 40 moves into an open position B when the protruding member 41 moves upward through the channel portion 36 and then up through the slit 40 (or the valve 30 moves downward over the member 41) as depicted in FIG. 13. Of course, as described above, the valve 30 can be pulled apart to expose the protruding member 41 rather than forced apart.

The channel portion 36 of the valve 30 can also operate as a sealing means around the protruding member 41. The sealing means helps provide a seal between the vascular system and the environment when the protruding member 41 has forced the slit 40 open. This sealing function is illustrated in FIG. 13 where the protruding member 41 is shown in its extended state, i.e., protruding above the valve 30. The channel portion 36 fits snugly around protruding member 41 so that it provides a seal. Optionally, a coating can be added to the inside of the channel portion 36 and/or the outside of the protruding member 41 to increase this sealing function. As shown in FIG. 12, the channel portion 36 can optionally contain a ring sealing member(s) 39 to increase the sealing function.

The advantage of valve 30 is that it can also serve as a flash-back chamber. If the valve 30 (and associated parts of the hub sheath) is made from a translucent or transparent material, it allows the user to view the inside of the valve 30. If sheath introducer 10 is placed in the proper location (i.e., in the venous system), blood will enter the valve chamber resulting in a red color as an indication that the sheath introducer is placed correctly. Using a translucent or transparent material for the valve 30 therefore allows the user to look through the valve and determine whether this red color is showing.

As mentioned above, a seal can be formed between the channel portion 36 and the protruding member 41. To help improve the seal between these two components, the protruding member 41 can be modified by providing stress risers (45 and 46) on the inside 40 and the outside 41 of the protruding member 41 as shown in FIG. 14. The internal stress riser 46 provides a smooth surface at the interface with the valve ring sealing member 39. As noted above, the valve ring sealing member 39 can provide a seal as the valve translates along the stem. Moving from the bottom to the top of the protruding member 41, the riser(s) 45 begin on the outside and then move to the inside 46, allowing the splitting mechanism (crack) to progress while maintaining a smooth outer surface between the valve ring sealing member 39 and the protruding member 41.

The stress riser 45 begins on the bottom of the sheath hub 47 and continues along the outside of the sheath hub until the stress riser 45 reaches a point below the initial location of the valve ring sealing member 39. At that point, the stress riser 46 moves to the inside of the protruding member 41 and then continues to the notch 50. The depth and width of the stress risers 45 and 46 are selected depending on the required separation force.

Another function of the stress risers 45 and 46 are to act as an initiator in the splitting process. By their nature, the stress risers are the beginning of a split in the hub sheath 47 and, therefore, can be used to make the splitting process easier. Accordingly, the stress risers 45 and 46 are located substantially on the axis where the introducer 10 will be split.

Another optional modification that can be made to the sheath introducer comprises notches 50 in the upper portion of the protruding member 41 that remain above the valve 30 in the extended position. The notches 50 give the protruding member 41 additional length to extend past the valve 30 while at the same time not adding additional length to the stress risers 45 and 46. Such a configuration adds length to the protruding member 41 without increasing the cracking force needed to split the introducer 10.

As shown in FIG. 14, the notches 50 are generally made to correspond with the same location as the stress risers 45 and 46, i.e., substantially along the axis of the expected split. The notches 50 can have any shape that results in a concentration of the stress force. Examples of such shapes include substantial “V” shape or the substantial rectangular shape shown in FIG. 14.

The sheath hub 47 can also be optionally modified to increase the attachment between the sheath hub 47 and the sheath 53. One manner to increase this attachment is depicted in FIGS. 15 and 16. In FIG. 15, the sheath has been modified to contain a sheath cap 57 with an interlocking fit between the sheath 53 and the sheath cap 57. The sheath cap 57 contains grooves 58 which provide a location for the split ends 55 of the sheath 53 when the sheath is inserted though the sheath cap 57. The ends of the split sheath fold around the sheath retention cap 57 with their location maintained in the grooves 58. Once the sheath retention cap 57 is assembled into the mating geometry of the sheath hub 47 as shown in FIG. 16, it locks the ends 55 of the split sheath tightly into the hub 47. The sheath cap 57 is then affixed to the sheath hub 47.

In some embodiments, the sheath cap 57 can affixed to the sheath hub 47 by means of a thermal, solvent or UV bond. In other embodiments, the sheath cap 57 can be affixed to the sheath hub 47 using a mechanical connection as known in the art, including a friction fit, snap fit, or ultrasonic weld. One example of such a mechanical connection is illustrated in FIG. 20, where the sheath hub 47 had been provided with a connector 72 containing male connections 71. The sheath cap 57 has also been provided with a corresponding shape and size that will mate with the connector 72, including female connections 73. When the sheath cap 57 is moved towards the sheath hub 47, the male connection 71 slides into the female connection 73 and attaches the hub 47 and the cap 57 to each other. Because of its shape, the cap 57 will also mate with the connector 72 and can be configured, as shown in FIG. 20, to retain the ends 74 of the sheath 53 between them.

Another method to increase the attachment sheath hub 47 and the sheath 53 is illustrated in FIG. 21. As shown in FIG. 21, the sheath cap 57 has been modified to contain extensions 75 that run substantially parallel to the body of the sheath hub 47. The extensions 75 have been configured to substantially match the body of sheath hub 47. Likewise, the body of sheath hub 47 has been configured to match the extensions of sheath cap 57. Although many matching configurations can be used, the extensions 75 contain ridges 77 that will substantially match notches 79 in the sheath hub. When the sheath cap 57 is moved towards the sheath hub 47, the ridges 77 slides into the notches 79 and attaches the hub 47 and the cap 57 to each other.

A similar, but different, configuration is depicted in FIGS. 22-23. In these Figures, the sheath hub bottom 107 has been modified to contain extensions 175 that run substantially parallel to the body of the sheath hub top 118. The extensions 175 have been configured to substantially match the body of sheath hub top 118. Likewise, the body of sheath hub top 108 has been configured to match the extensions of sheath hub bottom 107. Although many matching configurations can be used, the extensions 175 contain ridges 177 that will substantially match notches 179 in the sheath hub top 118 and then wrap over the ends 180 of the sheath hub bottom 107. When the sheath hub bottom 107 is moved towards the sheath hub top 118, the ridges 177 slides into the notches 179 and attaches the hub top 118 and the sheath hub bottom 107 to each other, with the wrapping portions of the sheath hub bottom 107 aiding the attachment.

Alternatively, another method to increase this attachment is depicted in FIG. 17. In FIG. 17, the sheath hub 47 has been modified to encapsulate an end portion of the sheath 53. This encapsulation is performed so that ridges 59 overly the end 56 of the sheath 53, thereby retaining the end of the sheath underneath the ridges.

In yet another modification, the sheath introducer can be provided with means for separating the valve housing 33 away from the sheath hub 47. Any known means for forcing these two components apart can be used in the invention, including leaf spring, coil spring, hinge, and/or a mechanical lever. As depicted in FIG. 18, the forcing means comprises a spring 65. In its compressed state, the valve housing 33 and the sheath hub 47 are attached to each other by any mechanism, such as the snap features 13 and 21 mentioned above and/or the lever 66. When the valve housing 33 and the sheath hub 47 are attached, the valve 30 remains closed. The moment the user separates the sheath hub 47 from the valve housing 33 by pressing on the grip section 52 (and/or disengaging the lever 66), the spring 65 is released from its compressed state and these two components separate from each other.

One result of the separation of these two components is the movement of valve 30 relative to the protruding member 41. When these two components are attached to each other, the spring is compressed and the valve 30 slides down the protruding member which then opens the slit 40 of the valve 30. When these components are separated, the pressure of the spring 65 is released and it returns to the uncompressed state, sliding the valve 30 back up the protruding member and closing the slit 40.

In another modification, the valve housing of the introducer could be engaged by means of a rotary movement along the axis of a threaded member or any other mechanical means to translate the valve housing along the desired path. For example, a mechanical lever, push button, or threaded member could be used in this modification.

In addition to any previously indicated variation, numerous other modifications and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the invention and appended claims are intended to cover such modifications and arrangements. Thus, while the invention has been described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred aspects of the invention, it will be apparent to those of ordinary skill in the art that numerous modifications, including but not limited to, form, function, manner of operations and use may be made without departing form the principles and concepts set forth herein. 

What is claimed is:
 1. A method of making a splittable sheath introducer, comprising: providing a splittable sheath; attaching a hub to a proximal end of the splittable sheath, the hub including a valve; and disposing a valve actuator in a cavity defined by the hub, the valve actuator movable from a first position to a second position to open the valve, the valve actuator comprising: a retaining feature that interacts with the hub to connect the retaining member to the hub; and a channel extending lengthwise through a side of the valve actuator to permit passage of a catheter.
 2. The method according to claim 1, wherein the retaining feature of the valve actuator includes a tongue longitudinally defined on an outer surface of the valve actuator, and wherein the hub includes a groove that receives the tongue of the valve actuator.
 3. The method according to claim 1, wherein the disposing includes disposing the valve actuator substantially coaxial with a longitudinal axis of the sheath introducer.
 4. The method according to claim 1, wherein the retaining feature comprises a plurality of interference features circumferentially defined in a longitudinally stacked arrangement about a portion of the valve actuator.
 5. The method according to claim 4, wherein the hub includes a plurality of teeth defined on an inner surface of the cavity, the teeth engaging the interference features when the valve actuator is moved toward the second position from the first position.
 6. The method according to claim 5, wherein the plurality of teeth prevent movement of the valve actuator back toward the first position after engagement with the interference features.
 7. The method according to claim 1, wherein the attaching further comprises positioning a top cap over the valve, the top cap including the cavity.
 8. The method according to claim 7, wherein the attaching further comprises inserting one or more valve extensions of the valve into corresponding indentations defined in the hub prior to the positioning.
 9. The method according to claim 8, wherein the attaching further comprises inserting one or more tabs of the top cap into corresponding grooves defined in the hub.
 10. The method according to claim 1, wherein the hub is formed from a translucent material to enable a user to view the cavity.
 11. The method according to claim 10, wherein the hub further includes a magnifier portion that magnifies a portion of the cavity.
 12. The method according to claim 1, wherein the valve actuator includes a top surface that enables the valve actuator to be pressed by a user from the first position to the second position. 